1. Field of the Invention
The present invention relates to a dry carbon dioxide (CO2) capturing device, and more specifically to a dry CO2 capturing device using multi sorbents so as to maintain the sorption rate for exhaust gas containing CO2 in which temperature rises by reacting with the sorbent containing CO2 absorbed therein.
2. Description of the Related Art
A carbon dioxide capture apparatus in related art generally employs a wet process to recover CO2. That is, the wet process is carried out by passing CO2-containing gas through an amine solution, to allow CO2 to be absorbed into the solution and regenerating the solution in a regeneration column, thus reusing the solution. However, the wet process has a demerit of further creating waste water during operation of the wet process.
In order to overcome disadvantages of the wet process in the art, a dry process for CO2 recovery has been proposed. This method is to recover CO2 by a dry processing system using two reactors, wherein CO2 fed into a recovery reactor is adsorbed to a solid adsorbent (a dry adsorbent) and removed. The solid adsorbent inflows into a regeneration reactor (‘regenerator’) to remove the adsorbed CO2, H2O is adsorbed to the solid adsorbent in a pre-treatment reactor, and then the adsorbent is recycled in a recovery reactor.
As shown in FIG. 3, the sorbent has an excellent sorption rate in a specific temperature range. Such a temperature range where the sorption rate of the sorbent is excellent is different according to the type of sorbent (see Esmail R. Monazam & Lawrence J. Shadle and Ranjani Siriwardane, Equilibrium and Absorption Kinetics of Carbon Dioxide by Solid Supported Amine Sorbent, Wiley Online Library, 2010).
Accordingly, the conventional method has a problem that the sorption rate of CO2 by the recovery reactor has a certain limit and if the temperature of exhaust gas in the recovery reactor is out of the temperature range the sorbent cannot perform its function satisfactorily.